The field of art to which this invention pertains is reduced and stabilized hydrogenation catalysts.
Finely divided reduced nickel catalysts have been used as hydrogenation catalysts for a large number of years. The preparation of such catalysts on diatomaceous earth or Kieselguhr is described, for example, in "Reactions of Hydrogen with Organic Compounds over Copper-Chromium Oxide and Nickel Catalysts" by Homer Adkins, University of Wisconsin Press (1937). Catalysts of this type are very sensitive to air in their activity to the point of being pyrophoric and, therefore, must be stabilized against the action of air in order to be utilized commercially.
U.S. Pat. No. 4,808,562 discloses processes for stabilizing finely divided pyrophoric catalysts by impregnating them with solid fats, solid paraffin, fatty amines or similar products.
Nickel catalysts dispersed in fat are described in U.S. Pat. No. 2,609,346.
According to U.S. Pat. No. 2,865,865, Raney nickel catalysts are mixed with a fatty alcohol to form a solid suspension of the catalyst in the fatty alcohol.
U.K. Patent No. 2,052,296 describes a process for stabilizing Raney metal catalysts. For example, a water wet Raney nickel catalyst is rendered oleophilic by a surface active agent followed by dispersing the oleophilic particles in molten wax, fat, or organic polymer and then solidifying the mixture. Examples of surface active agents, which are used in the amounts of 1/2 to 1 percent by weight based on the weight of catalyst and water, include the organic acid salts of long chain amines, such as tallow amine, soy bean oil amine and the like.
The use of nickel catalysts in the hydrogenation of nitriles to amines is well known and is described in such publications as "Reactions of Hydrogen with Organic Compounds" referred to hereinabove as well as U.S. Pat. Nos. 3,293,298, 3,163,676 and Japanese Patent No. 6464/55.